American lawyer Helen McGonigle, (50) who now campaigns for survivors of clerical sexual abuse, said the All Ireland Primate should resign for not alerting other families to Smyth’s horrific catalogue of abuse.

She was molested by Smyth in the late 1960s in Rhode Island, New York.

Speaking to BBC Radio Ulster today, Ms McGonigle said she was "outraged" by Cardinal Brady's response to allegations in a BBC documentary broadcast this week.

She said Cardinal Sean Brady's "duty as a human" was to protect children and his failure to act properly on Brendan Boland's complaint – when he named other five other children being abused - was "unforgivable".

The Cardinal had shown "arrogance and insensitivity", Ms McGonigle said.

She was just six-years-old and preparing for the sacrament of penance when she was abused by Smyth, who led her from her classmates into the sacristy of the church where he molested her.

Her sister, Kathleen, was also abused by the Belfast-born priest in their hometown of East Greenwich, Rhode Island, in the US. Unable to cope with the trauma of her devastated childhood, she took her own life as an adult.

Smyth was already known to have sexually molested children when he was sent to the McGonigles' parish in the summer of 1965. Using his usual modus operandi, he befriended the family and they bonded over a shared Irish ancestry.

Speaking to the Irish Independent two years ago, Ms McGonigle, who is an attorney living in Connecticut, said: "From 1967 until about 1970 he molested me. He was caught in my parish molesting children as early as 1968.

"It was in the spring of 1967, when myself and a neighbour were going through training to get the sacrament of penance, that he would pick us out one by one and bring us to the sacristy of the church to abuse us."

While any intervention by Cardinal Brady in 1975 would have been too late to save the children of East Greenwich, Ms McGonigle said many others could have been protected.

"Cardinal Brady has blood on his hands. He came to this with unclean hands.

"So many lives and children could have been spared. We know the reports of the number of Brendan Smyth's victims who committed suicide or attempted suicide."

She said Cardinal Brady must resign and he should be charged with obstruction of justice.

"He sat on this knowledge for 35 years, from 1975 through to 2010, and Brendan Smith continued to abuse children. It is only because of the lawsuit one of his victims has brought that he has had to show his hand."

She added: "How this is unfolding, we're seeing what the real church is. The real church has orchestrated this for decades. People need to take their church back."